title: PeerJ
description:  Articles published in PeerJ
link: https://peerj.com/articles/index.rss3?journal=peerj&page=721
creator: info@peerj.com PeerJ
errorsTo: info@peerj.com PeerJ
language: en

title: Diurnal pattern of salivary alpha-amylase and cortisol under citric acid stimulation in young adults
link: https://peerj.com/articles/13178
last-modified: 2022-04-12
description: BackgroundSaliva composition has diurnal variations. Citric acid stimulation plays a major role in the change of salivary flow rate and salivary composition. However, diurnal variations and sex differences in salivary alpha-amylase (sAA), pH, salivary flow rate (SFR), and salivary cortisol before and after citric acid stimulation remain unclear.MethodsWe recruited 30 healthy volunteers, including 15 women (24.7 ± 1.0 years old) and 15 men (25.3 ± 1.3 years old). At four time points (T1, 7:00; T2, 10:00; T3, 16:00; and T4, 20:00), saliva was collected from healthy volunteers before and after citric acid stimulation; and sAA, pH, SFR and salivary cortisol were measured and compared between men and women.ResultsThere were circadian fluctuations in sAA activity, SFR, pH, and cortisol level both before and after citric acid stimulation, and the diurnal fluctuations of these indexes were not affected by citric acid stimulation. There were significant differences in salivary cortisol between men and women before and after acid stimulation in T1. Neither SFR nor pH showed sex-related differences before or after acid stimulation. The variation trend of sAA activity was contrary to that of cortisol, with a significant negative correlation.ConclusionsOur data suggest that sAA and cortisol showed diurnal fluctuation, and the variation characteristics of male and female under resting state and acid stimulation were basically the same. The variation trend of salivary alpha-amylase activity was opposite to that of cortisol, with significant negative correlation. Our findings may enable the selection of the correct sampling time for research and the selection of appropriate sampling strategies in studies investigating chronic psychosocial conditions.
creator: Haimei Xie
creator: Xiaomei Zheng
creator: Ye Huang
creator: Weihao Li
creator: Wenkai Wang
creator: Qiao Li
creator: Jiangtao Hou
creator: Lulu Luo
creator: Xiuying Kuang
creator: Chuan-quan Lin
uri: https://doi.org/10.7717/peerj.13178
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2022 Xie et al.

title: Identification of the original plants of cultivated Bupleuri Radix based on DNA barcoding and chloroplast genome analysis
link: https://peerj.com/articles/13208
last-modified: 2022-04-12
description: Bupleuri Radix is the dry root of certain species of the genus Bupleurum and is commonly used in traditional Chinese medicine. The increasing global demand for Bupleuri Radix cannot be fulfilled with wild populations only. Therefore, cultivated Bupleurum is now the main commercial source of this medicinal product. Different species of Bupleurum show different medicinal properties and clinical effects, making reliable authentication and assignment of correct botanical origin for medicinal species critical. However, accurate identification of the cultivated Bupleurum species is difficult due to dramatic morphological variations resulting from cultivation. In this study, we sampled 56 cultivated Bupleurum populations of six different morphotypes (Types A-F) from the main production areas of China, and 10 wild populations of four species were used as reference materials. Conventional DNA barcoding was conducted to identify cultivated Bupleurum species. Additionally, verification based on complete chloroplast genomes was performed and new chloroplast markers were developed and evaluated. The combination of these methods resulted in the successful identification of all cultivated Bupleurum individuals. Three chloroplast regions are recommended as additional barcodes for the genus: ycf4_cemA, psaJ_rpl33, and ndhE_ndhG. This is a reliable and promising strategy that can be applied to the authentication of natural products and the identification of other medicinal plant species with similar taxonomic problems.
creator: Gaixia Zhang
creator: Hui Wang
creator: Linchun Shi
creator: Yang Liu
creator: Ruyu Yao
creator: Chun Sui
creator: Chengmin Yang
creator: Hongliang Ji
creator: Qiuling Wang
creator: Jianhe Wei
uri: https://doi.org/10.7717/peerj.13208
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2022 Zhang et al.

title: Effect of extracts from eggs of Helix aspersa maxima and Helix aspersa aspersa snails on Caco-2 colon cancer cells
link: https://peerj.com/articles/13217
last-modified: 2022-04-12
description: BackgroundColorectal cancer is the third most commonly diagnosed cancer. Natural compounds, administered together with conventional chemotherapeutic agent(s) and/or radiotherapy, may be a novel element in the combination therapy of this cancer. Considering the anticancer properties of compounds derived from different tissues of various snail species confirmed earlier, the purpose of the present research was to evaluate the effect of extracts from eggs of Helix aspera maxima and Helix aspersa aspersa snails, and fractions of extracts containing particles of different molecular weights on Caco-2 human epithelial colorectal adenocarcinoma cells.MethodsThe extracts and fractions were analyzed for antioxidant activity, phenols and total carbohydrates using colorimetric methods. Lipid peroxidation products and glutathione in eggs were also examined using these methods. Crude protein and fat in eggs were determined. Molecular weights of egg proteins and glycoproteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Astaxanthin, selected vitamins and amino acids in eggs were measured using liquid chromatography methods, and minerals by emission spectroscopy, mass spectrometry or X-ray fluorescence. The action of extracts on the cell viability was determined by the MTT (methylthiazolyldiphenyl-tetrazolium bromide) test, based on the mitochondrial oxidative activity, after 24 and 72 h of treatment. The influence of fractions on the cell viability was assayed after 24 h. The effect of extracts on the percentage of live and dead cells was evaluated by the trypan blue assay, in which live cells exclude trypan blue, while dead cells take up this dye, after 12, 24, 48 and 72 h of treatment. Their influence on the integrity of cell membranes was determined based on the activity of LDH (lactate dehydrogenase), released from damaged cells, after 24 and 72 h of treatment. Then, the effect of extracts on the content of lipid peroxidation products in cells was examined using colorimetric method, after 24 h of treatment. Their influence on types of cell death was determined by flow cytometry, after this time.ResultsThe extracts and their fractions containing molecules <3 kDa decreased the cell viability, after 24 h of treatment. The extracts reduced the percentage of live cells (also after 48 h), increased the degree of cell membrane damage and the amount of lipid peroxidation products, induced apoptosis and reduced necrosis.ConclusionsAntioxidants, phenols, lipid peroxidation products, anticancer peptides, restriction of methionine, appropriate ratio of essential amino acids to non-essential amino acids, vitamin D3, Ca, Mg, S, Cu, Mn, Zn, Se and other bioactive compounds comprised in the extracts and their additive and synergistic effects may have influenced Caco-2 cells. Natural extracts or the chemical compounds contained in them might be used in the combination therapy of colorectal cancer, which requires further research.
creator: Magdalena Matusiewicz
creator: Karolina Marczak
creator: Barbara Kwiecińska
creator: Julia Kupis
creator: Klara Zglińska
creator: Tomasz Niemiec
creator: Iwona Kosieradzka
uri: https://doi.org/10.7717/peerj.13217
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2022 Matusiewicz et al.

title: New insights into the cranial osteology of the Early Cretaceous paracryptodiran turtle Lakotemys australodakotensis
link: https://peerj.com/articles/13230
last-modified: 2022-04-12
description: Lakotemys australodakotensis is an Early Cretaceous paracryptodire known from two shells and a skull from the Lakota Formation of South Dakota, USA. Along with the Early Cretaceous Arundelemys dardeni and the poorly known Trinitichelys hiatti, Lakotemys australodakotensis is generally retrieved as an early branching baenid, but more insights into the cranial anatomy of these taxa is needed to obtain a better understanding of paracryptodiran diversity and evolution. Here, we describe the skull of Lakotemys australodakotensis using micro-computed tomography to provide the anatomical basis for future phylogenetic analyses that will be needed to investigate more precisely the intrarelationships of Paracryptodira. Preliminary comparisons reveal that the cranial anatomy of Lakotemys australodakotensis is very similar to that of the Aptian-Albian basal baenid Arundelemys dardeni, that both taxa exhibit a remarkable combination of derived characters found in baenodds and characters found in non-baenid paracryptodires, particularly Pleurosternidae, and that Lakotemys australodakotensis is the only known baenid to date to possess a canal for the palatine artery.
creator: Yann Rollot
creator: Serjoscha W. Evers
creator: Richard L. Cifelli
creator: Walter G. Joyce
uri: https://doi.org/10.7717/peerj.13230
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2022 Rollot et al.

title: Physical activity questionnaire for older children (PAQ-C): Arabic translation, cross-cultural adaptation, and psychometric validation in school-aged children in Saudi Arabia
link: https://peerj.com/articles/13237
last-modified: 2022-04-12
description: The validity of the Physical Activity Questionnaire for Older Children (PAQ-C) has been mostly studied in North America and Europe. We investigated the psychometric validation of the Arabic version of the PAQ-C in students in Saudi Arabia. The students (n = 327, age = 8–14 years) of six primary schools in the Majmaah region participated in the study. Participants completed the PAQ-C, and their demographics were recorded. The PAQ-C scores satisfied the following factor analysis assumptions: diagonal elements of the anti-image correlation matrix (>0.5), Bartlett’s test of sphericity (p < 0.001), determinant (>0.00001), Kaiser–Meyer–Olkin test of sampling adequacy (>0.8), and communality (all values > 0.2). Exploratory factor analysis results were inconclusive, with two measures favoring a 2-factor solution (Kaiser’s criteria (Eigenvalue ≥ 1), and cumulative variance rule (>40%)); whereas, the scree test and the Monte Carlo parallel analysis favored a 1-factor structure. The confirmatory factor analysis favored a 1-factor solution: highest CFI, lowest RMSEA, non-significant χ2 statistics, and lowest χ2/df. The values of item-total correlation, corrected item-total correlation, and Cronbach’s alpha if an item was deleted, ranged from 0.20–0.57, 0.42–0.64, and 0.70–0.75, respectively. The PAQ-C showed a Cronbach’s alpha of 0.74. A 1-factor structure of the Arabic version of the PAQ-C had adequate psychometric validity in schoolchildren in Saudi Arabia.
creator: Mohamed Sherif Sirajudeen
creator: Mohamed Waly
creator: Md. Dilshad Manzar
creator: Mazen Alqahtani
creator: Msaad Alzhrani
creator: Ahmad Alanazi
creator: Radhakrishnan Unnikrishnan
creator: Hariraja Muthusamy
creator: Rashmi Saibannavar
creator: Wafa Alrubaia
uri: https://doi.org/10.7717/peerj.13237
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2022 Sirajudeen et al.

title: Phylogeny, distribution and potential metabolism of candidate bacterial phylum KSB1
link: https://peerj.com/articles/13241
last-modified: 2022-04-12
description: Candidate phylum KSB1 is composed of uncultured bacteria and has been reported across various environments. However, the phylogeny and metabolic potential of KSB1 have not been studied comprehensively. In this study, phylogenomic analysis of KSB1 genomes from public databases and eleven metagenome-assembled genomes (MAGs) from marine and hydrothermal sediments revealed that those genomes were clustered into four clades. Isolation source and relative abundance of KSB1 genomes showed that clade I was particularly abundant in bioreactor sludge. Genes related to dissimilatory reduction of nitrate to ammonia (DNRA), the last step of denitrification converting nitrous oxide to nitrogen and assimilatory sulfur reduction were observed in the expanded genomes of clade I, which may due to horizontal gene transfer that frequently occurred in bioreactor. Annotation and metabolic reconstruction of clades II and IV showed flagellum assembly and chemotaxis genes in the genomes, which may indicate that exploration and sensing for nutrients and chemical gradients are critical for the two clades in deep-sea and hydrothermal sediment. Metabolic potentials of fatty acids and short-chain hydrocarbons utilization were predicted in clades I and IV of KSB1. Collectively, phylogenomic and metabolic analyses of KSB1 clades provide insight into their anaerobic heterotrophic lifestyle and differentiation in potential ecological roles.
creator: Qingmei Li
creator: Yingli Zhou
creator: Rui Lu
creator: Pengfei Zheng
creator: Yong Wang
uri: https://doi.org/10.7717/peerj.13241
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2022 Li et al.

title: Factors related to overweight and obese populations maintaining metabolic health
link: https://peerj.com/articles/13242
last-modified: 2022-04-12
description: BackgroundFor people who are overweight or obese, maintaining a metabolically healthy status can decrease the risks of developing cardiovascular diseases and Type 2 diabetes. Despite this, only a limited amount of research has discussed the metabolically healthy overweight and obesity (MHOO) population in Asia and the factors associated with them maintaining their metabolic health.MethodsThis study enrolled 195 MHOO participants from communities in northern Taiwan during 2009–2010 (baseline). Of the 195 participants, 89 completed the follow-up assessment after a median follow-up time of nine years. Body type was determined by body mass index (BMI, kg/m2). We defined overweight as a BMI ≥ 24 kg/m2 and <27 kg/m2 and defined obese as a BMI ≥ 27 kg/m2. Metabolic health was defined as the absence of cardiometabolic diseases and the presence of ≤1 of the cardiometabolic risk factors, namely hypertension, hyperglycemia, hypertriglyceridemia, and low serum high-density lipoprotein cholesterol. Metabolic health, BMI, and other covariates were evaluated at both baseline and follow-up. Generalized estimating equations (GEE) models were used to analyze the factors associated with maintenance of metabolic health during the follow-up period.ResultsAt baseline, the mean age of the study participants was 47.4 (SD 5.3) years and 46 (51.7%) of the participants were women. There were 51 (57.3%) individuals who maintained their metabolic health status at the time of the nine-year follow-up. The detrimental factors pertaining to metabolic health included older age, longer duration until follow-up, BMI ≥ 27 kg/m2, and increase in waist circumference. No significant relationships were observed between sociodemographic factors and lifestyle factors, such as sex, level of education, cigarette smoking, alcohol consumption, and physical activity, and sustained metabolic health among MHOO individuals.ConclusionsTo maintain metabolic health and prevent negative changes in health status, control of bodyweight and waist circumference should remain a priority for MHOO individuals even when there are no metabolic disorders present.
creator: Yi-Hsuan Lin
creator: Hsiao-Ting Chang
creator: Yen-Han Tseng
creator: Harn-Shen Chen
creator: Shu-Chiung Chiang
creator: Tzeng-Ji Chen
creator: Shinn-Jang Hwang
uri: https://doi.org/10.7717/peerj.13242
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2022 Lin et al.

title: Icaritin attenuates 6-OHDA-induced MN9D cell damage by inhibiting oxidative stress
link: https://peerj.com/articles/13256
last-modified: 2022-04-12
description: BackgroundWe assessed whether ICT can alleviate 6-OHDA-induced cell damage via inhibition of oxidative stress by evaluating the protective effect of icaritin (ICT) against 6-hydroxydopamine (6-OHDA)-induced MN9D cell damage and further determined the mechanism by which ICT reduces oxidative stress.MethodsMN9D cells were treated with 6-OHDA, to study the mechanism underlying the neuroprotective effect of ICT. MN9D cell damage was assessed by the CCK-8 assay, flow cytometry was performed to measure the content of reactive oxygen species (ROS) in cells, a superoxide dismutase (SOD) kit was used to evaluate SOD activity, and Western blotting was used to measure the expression of α-synuclein (α-Syn), Tyrosine hydroxylase (TH), nuclear factor erythroid-2 related factor 2 (Nrf2), and heme oxygenase-1 (HO-1).ResultsICT reduced damage to MN9D cells induced by 6-OHDA. ICT increased SOD activity and TH expression and reduced ROS production and α-Syn expression. ICT promoted the translocation of Nrf2 from the cytoplasm to the nucleus and further increased the protein expression of HO-1.ConclusionsICT protects against 6-OHDA-induced dopaminergic neuronal cell injury by attenuating oxidative stress, and the mechanism is related to modulate the activities of Nrf2, HO-1 protein, and SOD.
creator: Xinyu Zhou
creator: Nanqu Huang
creator: Xiaoyi Hou
creator: Li Zhu
creator: Yiman Xie
creator: Zhisheng Ba
creator: Yong Luo
uri: https://doi.org/10.7717/peerj.13256
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2022 Zhou et al.

title: Expression and promoter analysis of MEP pathway enzyme-encoding genes in Pinus massoniana Lamb
link: https://peerj.com/articles/13266
last-modified: 2022-04-12
description: The methylerythritol phosphate (MEP) pathway provides the universal basic blocks for the biosynthesis of terpenoids and plays a critical role in the growth and development of higher plants. Pinus massoniana is the most valuable oleoresin producer tree with an extensive terrestrial range. It has the potential to produce more oleoresin with commercial value, while being resistant to pine wood nematode (PWN) disease. For this study, eleven MEP pathway associated enzyme-encoding genes and ten promoters were isolated from P. massoniana. Three PmDXS and two PmHDR existed as multi-copy genes, whereas the other six genes existed as single copies. All eleven of these MEP enzymes exhibited chloroplast localization with transient expression. Most of the MEP genes showed higher expression in the needles, while PmDXS2, PmDXS3, and PmHDR1 had high expression in the roots. The expressions of a few MEP genes could be induced under exogenous elicitor conditions. The functional complementation in a dxs-mutant Escherichia coli strain showed the DXS enzymatic activities of the three PmDXSs. High throughput TAIL PCR was employed to obtain the upstream sequences of the genes encoding for enzymes in the MEP pathway, whereby abundant light responsive cis-elements and transcription factor (TF) binding sites were identified within the ten promoters. This study provides a theoretical basis for research on the functionality and transcriptional regulation of MEP enzymes, as well as a potential strategy for high-resin generation and improved genetic resistance in P. massoniana.
creator: Peihuang Zhu
creator: Yu Chen
creator: Fan Wu
creator: Miaojing Meng
creator: Kongshu Ji
uri: https://doi.org/10.7717/peerj.13266
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2022 Zhu et al.

title: Ecomorphospace occupation of large herbivorous dinosaurs from Late Jurassic through to Late Cretaceous time in North America
link: https://peerj.com/articles/13174
last-modified: 2022-04-11
description: Following the Late Jurassic, megaherbivore communities in North America undergo a dramatic turnover in faunal composition: sauropods decline to the point of becoming relatively minor components of ecosystems, stegosaurs become extinct, and hadrosaurids, ceratopsids and ankylosaurs rise in diversity and abundance. Although a variety of causes have been proposed to account for the dramatic decrease in sauropod diversity following the Late Jurassic and could have also been applicable to the disappearance of stegosaurs, the potential for competitive replacement of sauropods by hadrosauroids as an explanation has been previously dismissed due to morphological differences without further investigation. Using twelve ecomorphological correlates of the skull, this study provides a preliminary investigation into ecomorphospace occupation of major megaherbivore clades from the Late Jurassic through to the Late Cretaceous of North America and assess if morphological differences were enough to have potentially facilitated dietary niche partitioning between sauropods and iguanodontians and stegosaurs and ankylosaurs. Overlap in reconstructed ecomorphospace was observed between sauropods (particularly non-diplodocid sauropods) and iguanodontians, as would be expected if morphological differences were not enough to facilitate niche partitioning, contrary to original claims used to dismiss the competitive replacement hypothesis. Overlap was also observed between stegosaurs and ankylosaurs, particularly between Late Cretaceous ankylosaurs. Whether this overlap is reflective competitive replacement or opportunistic occupation of recently vacated niches will require further assessment as sampling of some clades prior to the Late Cretaceous is too poor to make a reliable assessment and several underlying assumptions necessary for competition to occur (e.g., resource limitation) still need investigation. Teasing out the cause(s) of the ‘sauropod decline’ and extinction of stegosaurs in North America following the Late Jurassic will require future research not only into the competitive exclusion hypothesis, but other hypotheses as well with better sampling from Early Cretaceous and Late Jurassic intervals.
creator: Taia Wyenberg-Henzler
uri: https://doi.org/10.7717/peerj.13174
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2022 Wyenberg-Henzler